1. Field of the Invention
This invention relates to a pneumatic tire and more particularly to a pneumatic radial tire for all-season passenger car use.
2. Description of Related Art
As shown in FIG. 3, the conventionally typical pneumatic radial tire for all-season passenger car use had a tread pattern in which many blocks were formed at given intervals in an axial direction and in a circumferential direction of the tire by a plurality of circumferential grooves straightforward extending in the circumferential direction and a plurality of slant grooves each extending at an inclination angle of about 45° with respect to the circumferential direction.
In this type of the pneumatic radial tire for all-season passenger car use, it is required to have various performances such as drainage property in the while running on a wet road surface, steering stability while running on a dry road surface, snow performances in the running on snow, e.g. braking performance, traction performance, straight running performance, cornering performance and the like, resistance to uneven wear and so on.
Recently, it is demanded to develop pneumatic radial tires for all-season passenger car developing an excellent drainage property in the running on wet road surface without substantially sacrificing the steering stability while running on a dry road surface, the snow performances and the resistance to uneven wear.